This research program is concerned with the structural proteins in the vitreous which are responsible for the gel state of the tissue. Fractionation and chemical studies will be carried out to determine the composition of the CNBr peptides derived from the helical region of the collagen fibers and the structure of the non-helical peptide constituents. Aggregation and electron microscopy studies will be performed to compare the structure and thermal stability of in vitro assembled bovine vitreous and cartilage collagens. Similar comparative studies will also be carried out on human, ovine, rabbit and dog vitreous collagens. The major glycoprotein constituents in bovine vitreous will be isolated and purified and experiments carried out to determine if these constituents interact with vitreous collagen.